Fluctuation-induced nucleation and dynamics of kinks on dislocation: Soliton and oscillation regimes in the two-dimensional Frenkel-Kontorova model

Numerical simulation of the dislocation motion in two-dimensional Frenkel-K ontorova model in the thermostat shows an unusual dynamical behavior. It ap pears that "kink" regime of dislocation gliding takes place in a certain re gion of parameters of the model but, in disagreement with the common views about the dislocation motion under plastic deformation condition, the kinks appear to be similar to sine-Gordon solitons despite the discreteness of t he lattice, damping, and thermal fluctuations. At high enough stresses and temperatures the motion of the dislocation is accompanied by its oscillatio ns rather than kink nucleation. [S0163-1829(99)02125-6].